Stockholders' Equity (Schedule of Reclassifications out of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 27, 2020	Jun. 28, 2020	Mar. 29, 2020	Dec. 31, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Net revenue	$ 367,073	$ 378,114	$ 280,052	$ 229,963	$ 252,971	$ 265,858	$ 230,852	$ 249,082	$ 1,255,202	$ 998,763	$ 1,058,816
Cost of revenue									883,050	704,535	717,118
Research and development									88,788	77,982	82,416
Sales and marketing									147,854	138,150	152,569
General and administrative									61,148	49,432	64,857
Income before income taxes									70,803	29,571	43,204
Tax impact from continuing operations	(2,531)	(6,214)	(3,247)	(518)	(1,045)	228	(756)	(2,207)	(12,510)	(3,780)	(25,878)
Net income from continuing operations									58,293	25,791	17,326
Net loss from discontinued operations, net of tax									0	0	(35,655)
Net income (loss)	$ 30,948	$ 25,535	$ 5,983	$ (4,173)	$ (420)	$ 12,529	$ 839	$ 12,843	58,293	25,791	(18,329)
Amount Reclassified from AOCI
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Net revenue									(954)	1,929	665
Cost of revenue									2	(12)	(9)
Research and development									9	(57)	83
Sales and marketing									124	(284)	(102)
General and administrative									27	(41)	(53)
Income before income taxes									(792)	1,535	584
Tax impact from continuing operations									166	(322)	(123)
Net income from continuing operations									(626)	1,213	461
Net loss from discontinued operations, net of tax									0	0	4
Net income (loss)									$ (626)	$ 1,213	$ 465